<template>
  <view>
    <view class="search-box">
        <!-- 使用自定义的搜索组件 -->
        <my-search @click="gotoSearch"></my-search>
     
    </view>  
    <view class="scroll-view-container">
     <!-- 左侧的滚动视图区域 -->
     <scroll-view class="left-scroll-view" scroll-y :style="{height: wh + 'px'}">
     <block v-for="(item, i) in cateList" :key="i">
       <view :class="['left-scroll-view-item', i === active ? 'active' : '']">{{item.cat_name}}</view>
     </block>
     </scroll-view>
       
      </scroll-view>
      <!-- 右侧的滚动视图区域 -->
      <scroll-view class="right-scroll-view" scroll-y :style="{height: wh + 'px'}" :scroll-top="scrollTop">
        <view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
            <view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
             <view class="cate-lv3-list">
      <!-- 三级分类 Item 项 -->
      <view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
        <!-- 图片 -->
        <image :src="item3.cat_icon"></image>
        <!-- 文本 -->
        <text>{{item3.cat_name}}</text>
      </view>
    </view>
          </view>
      </scroll-view>
    </view>
  </view>
</template>
<script>
  export default {
    data() {
      return {
         // 滚动条距离顶部的距离
            scrollTop: 0,
        //当前选中项索引默认选中第一个
        active:0,
        // 二级分类列表
            cateLevel2: [],
          wh: 0,
       // 分类数据列表
       cateList: []
      };
    },
    onLoad() {
          // 获取当前系统的信息
          const sysInfo = uni.getSystemInfoSync()
          // 为 wh 窗口可用高度动态赋值
          this.wh = sysInfo.windowHeight - 50
           // 调用获取分类列表数据的方法
            this.getCateList()
        },

       methods: {
        async getCateList() {
          const { data: res } = await uni.$http.get('/api/public/v1/categories')
          if (res.meta.status !== 200) return uni.$showMsg()
          this.cateList = res.message
          // 为二级分类赋值
          this.cateLevel2 = res.message[0].children
        },
          activeChanged(i) {
             this.active = i,
               this.cateLevel2 = this.cateList[i].children
               this.scrollTop = this.scrollTop === 0 ? 1 : 0

           },
           // 点击三级分类项跳转到商品列表页面
           gotoGoodsList(item3) {
             uni.navigateTo({
               url: '/subpkg/goods_list/goods_list?cid=' + item3.cat_id
             })
           },
           gotoSearch() {
                uni.navigateTo({
                  url: '/pages/search/search'
                })
              }
       }
  }
</script>

<style lang="scss">
.scroll-view-container {
  display: flex;

  .left-scroll-view {
    width: 120px;

    .left-scroll-view-item {
      line-height: 60px;
      background-color: #f7f7f7;
      text-align: center;
      font-size: 12px;

      // 激活项的样式
      &.active {
        background-color: #ffffff;
        position: relative;

        // 渲染激活项左侧的红色指示边线
        &::before {
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #c00000;
          position: absolute;
          left: 0;
          top: 50%;
          transform: translateY(-50%);
        }
      }
    }
  }
}
.cate-lv3-list {
  display: flex;
  flex-wrap: wrap;

  .cate-lv3-item {
    width: 33.33%;
    margin-bottom: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;

    image {
      width: 60px;
      height: 60px;
    }

    text {
      font-size: 12px;
    }
  }
}
.cate-lv2-title {
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
}
.search-box {
  // 设置定位效果为“吸顶”
  position: sticky;
  // 吸顶的“位置”
  top: 0;
  // 提高层级，防止被轮播图覆盖
  z-index: 999;
}
</style>
